First-in-class PD-1/IL-2α-bias bispecific antibody fusion protein IBI363 combined with bevacizumab in patients with advanced colorectal cancer: Results from Phase 1 study

This Phase 1 study was conducted to evaluate the safety, tolerability and preliminary efficacy of IBI363 combined with bevacizumab in subjects with advanced colorectal cancer.

A total of 35 subjects received treatment of IBI363 combined with bevacizumab, demonstrating promising anti-tumor efficacy with good tolerability and safety

• As of the data cutoff date (Aug 30, 2024), a total of 35 subjects with advanced colorectal cancer received combination treatment at 3 different dose levels (0.6 mg/kg IBI363 combined with 5 mg/kg bevacizumab Q2W, 1 mg/kg IBI363 combined with 5 mg/kg bevacizumab Q2W, and 1.5 mg/kg IBI363 combined with 7.5 mg/kg bevacizumab Q3W). Among them, 91.4% of the subjects had advanced colorectal cancer with microsatellite stable (MSS) or proficient mismatch repair (pMMR), and the MSI/MMR status was unknown in 8.6% subjects. 91.4% of the subjects had previously received 2 or more lines of systemic anti-tumor treatment. 51.4% of the subjects had liver metastases. 25.7% of the subjects had received prior immunotherapy. 40% of the subjects had KRAS/NRAS exon 2/3/4 mutations.
• The most common treatment related adverse events (TRAEs) were arthralgia, thyroid disorders, and rash. The total incidence of TRAEs ≥ grade 3 was 22.9%. Immune related adverse events (irAEs) ≥ grade 3 occurred in 5.7% of subjects. The safety profile of the combination regimen was similar to that of IBI363 monotherapy, and no new safety signals were identified.